Dual clutch countershaft automatic transmission

Abstract

A countershaft automatic transmission for vehicular use is disclosed. The transmission has four forward gears which operate using two clutches and two dual synchronizers, The two clutches are mounted on a main shaft with associated gear clusters and the synchronizers are mounted on a countershaft with associated mating gear clusters. Reverse gear uses another synchronizer mounted on a lay shaft with associated gearing. Gear engagement is accomplished by actuating a hydraulic clutch after having shifted a synchronizer to select the gear to be engaged.

What is claimed is: 
     
       1. An automatic transmission comprising: a transmission housing;   a main shaft rotatably mounted in said housing;   a countershaft in said housing spaced from and parallel to said main shaft;   first gearing mounted on said main shaft;   second gearing mounted on said main shaft;   first clutch means and second clutch means mounted on said main shaft for respectively connecting selectively said first gearing and said second gearing to said main shaft, said first and second clutch means being disposed between said first and second gearing and being located respectively adjacent said first gearing and said second gearing;   third gearing and fourth gearing mounted on said countershaft in engagement with said first gearing;   fifth gearing and sixth gearing mounted on said countershaft in engagement with said second gearing;   said transmission comprising further first synchronizer clutch means on said countershaft for synchronously connecting said third gearing and said fourth gearing to said countershaft and second synchronizer clutch means on said countershaft for synchronously connecting said fifth gearing and said sixth gearing to said countershaft;   a lay shaft arranged in parallel disposition with respect to said main shaft and a first reverse gear on said lay shaft engaging said first gearing.   
     
     
       2. A transmission as set forth in claim 1 including a second reverse gear mounted on and connected to said lay shaft engageable with both said second gearing on said main shaft and said sixth gearing on said countershaft. 
     
     
       3. The combination as set forth in claim 2 wherein said transmission comprises a third synchronizer clutch means on said lay shaft for connecting said first reverse gear to said lay shaft synchronously. 
     
     
       4. The combination as set forth in claim 3 wherein said transmission comprises a parking wheel, said parking wheel being positioned on said lay shaft. 
     
     
       5. The combination as set forth in claim 4 wherein said parking wheel forms a part of said second synchronizer clutch means.